The present invention relates to a compound of Formula or a pharmaceutically acceptable salt thereof which is useful for the treatment of conditions associated with glutamate hypofunction, such as psychiatric and neurological disorders. The laser pump source has a pulse duration that may be short enough to gain switch a particular transition or long enough to allow end-pumping with high energy densities without damage. Each sense amplifier compares a series of reference voltages to a corresponding bit line and sets a result value for the comparison. A controller in the control hub analyzes the digital output from each signal processor to determine one or more characteristics of the sensor network.